package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.hmdp.dto.Result;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.FollowMapper;
import com.hmdp.service.IFollowService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IUserService;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 * 服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class FollowServiceImpl extends ServiceImpl<FollowMapper, Follow> implements IFollowService {

    @Resource
    private StringRedisTemplate stringRedisTemplate;

    @Resource
    private IUserService userService;

    @Override
    public Result follow(Long id, Boolean isFollow) {
        //1.获取当前登录用户
        Long userId = UserHolder.getUser().getId();
        String key = "follow:" + userId;
        //2.判断是否关注
        if (!isFollow) {
            //3.已经关注了，取消关注
            LambdaQueryWrapper<Follow> queryWrapper = new LambdaQueryWrapper<>();
            queryWrapper.eq(Follow::getUserId, userId);
            queryWrapper.eq(Follow::getFollowUserId, id);
            boolean isRemove = this.remove(queryWrapper);
            if (isRemove) {
                stringRedisTemplate.opsForSet().remove(key, id.toString());
            }
        } else {
            //4.没有关注，关注
            Follow follow = new Follow();
            follow.setFollowUserId(id);
            follow.setUserId(userId);
            boolean isSave = this.save(follow);
            if (isSave) {
                stringRedisTemplate.opsForSet().add(key, id.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result isFollow(Long id) {
        Long userId = UserHolder.getUser().getId();
        LambdaQueryWrapper<Follow> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(Follow::getUserId, userId);
        queryWrapper.eq(Follow::getFollowUserId, id);
        long count = this.count(queryWrapper);
        return count <= 0 ? Result.ok(false) : Result.ok(true);
    }

    @Override
    public Result followCommon(Long id) {
        Long userId = UserHolder.getUser().getId();
        String key = "follow:" + userId;
        String key2 = "follow:" + id;
        Set<String> intersect = stringRedisTemplate.opsForSet().intersect(key, key2);
        if (intersect == null || intersect.isEmpty()) {
            return Result.ok(Collections.EMPTY_LIST);
        }
        List<Long> ids = intersect.stream().map(Long::valueOf).collect(Collectors.toList());
        List<UserDTO> res = ids.stream().map(item -> {
            UserDTO userDTO = new UserDTO();
            User user = userService.getById(item);
            BeanUtil.copyProperties(user, userDTO);
            return userDTO;
        }).collect(Collectors.toList());
        return Result.ok(res);
    }
}
